The Present Invention is in the field of integrated circuit fabrication and particularly materials of construction in the films that are adjacent to or are a part of electronic devices in the integrated circuit, such as transistors, capacitors, vias, electrically conductive lines and buss bars. As the dimensions of such electronic devices continue to shrink and the density of such devices in a given area increases, the films adjacent to or a part of such electronic devices must exhibit higher electrical properties. Designing stress into such films can alter their electrical properties. Stress engineering of PECVD silicon nitride films is currently being used to enhance the performance of cutting edge metal oxide semiconductor field effect transistor (MOSFET) technology. Device speed has been significantly increased through the application of highly stressed SiN films deposited on top of MOSFET gate structures. Compressive stress enhances “P” type field effect transistors (pFET) devices through increases of hole mobility, while tensile stress is beneficial for “N” type field effect transistors (nFET) devices through enhancing electron mobility. Stress is generated from differences in the thermal expansion between two materials in contact. Plasma enhanced chemical vapor deposition (PECVD) silicon nitride films generally generate compressive stress. Presently, compressively stressed films are deposited using silane and ammonia with reported compressive stresses up to ˜−3.5 giga pascales (GPa). Increasing compressive stress further is becoming particularly challenging. The industry is currently aiming for compressively stressed films of −4 GPa or higher.
Patents related to this technology include: US 2006/0045986; EP 1 630 249; US 2006/0258173; EP 1 724 373; U.S. Pat. No. 7,288,145; U.S. Pat. No. 7,122,222; US20060269692; WO2006/127462; and US2008/0146007, as well as the literature reference; “Methods of producing plasma enhanced chemical vapor deposition silicon nitride thin films with high compressive and tensile stress.”; M. Belyansky et al. J. Vac. Sci. Technol. A 26(3), 517 (2008).